Current design trends for computing devices having touch screen interfaces such as tablets or mobile phones include designs having an increase in power, a decrease in size (e.g., thickness), and an increase in speed. As the thickness of the computing device is reduced, certain internal device components are positioned closer together. This provides for challenges in manufacturing design and thermal management.
Specifically, with regard to manufacturing design, current touch screen computing devices may have problems with visual distortions appearing on the display screen when an input force is applied to the display screen (e.g., via a finger or stylus). For example, a liquid crystal display (LCD) device may have problems with “pooling” when a user applies pressure to the display screen of the LCD device, wherein a realignment of liquid crystal molecules occurs. This input pressure alters the state of the affected crystals and thereby locally alters the image by color and/or intensity changes.
Visual distortion or pooling may occur at the location of the application of pressure, otherwise referred to as localized distortion or localized pooling. Additionally or alternatively, visual distortion or pooling may occur at a location where an internal device component (e.g., battery, processor, integrated circuit, printed circuit board) positioned beneath the display unit is pressed into the display unit when the user applies pressure to the screen. This distortion may be referred to as component distortion or component pooling. The component distortion may not necessarily be positioned beneath the location of applied pressure, which may be referred to as remote pooling. As such, the user operating the device may notice a distorted display at a position separate from the location of applied pressure and become concerned that something is wrong with the device. In some cases, the component distortion may mark or permanently damage the display unit, potentially creating a permanently distorted display.